Many conventional technologies are routinely practiced by law enforcement agencies to identify a perpetrator, including fingerprinting, video surveillance, and foot printing. Each also is a deterrent to the commission of crime since criminals know that their widespread use makes it more likely that a perpetrator can be identified and prosecuted.
These methodologies have their limitations, however, because each can be defeated or at least countered by the criminal. Use of gloves or a facemask, for example, defeats identification by fingerprinting or video surveillance.
Defenses against crimes of intrusion by potential victims routinely include handguns, mace, stunning devices and the like, which have in common the requirement that the victim must brandish the deterring weapon in close proximity to the criminal intruder. Besides being daunting and dangerous to the victim acting in self-defense, confronting seasoned criminals does not necessarily result in identification. Confronted by weapons, it is all too usual for the criminal to “get the drop” on the victim, or to withdraw from the crime scene. In either case the criminal is not likely to be identified.